Deadlock Between Separatists, Other Factions in National Dialogue Causes Postponement

BEIRUT—Yemen has delayed a November constitutional referendum that would pave the way for the country's first free elections, as southern secessionists hold fast to demands for their own state and as the capital's grip on security slips further, after armed men killed a German Embassy employee and a United Nations worker was kidnapped over the weekend.

The secessionist movement Hirak also called for a million-man march on Saturday to protest against a constitution that would keep Yemen unified. The movement has popular...